Performance Analysis of Uplink Rate-Splitting Multiple Access with Hybrid ARQ

TL;DR

This paper evaluates uplink rate-splitting multiple access (RSMA) combined with hybrid ARQ, demonstrating its superior reliability and power efficiency over NOMA and FDMA through a novel retransmission and power allocation scheme.

Contribution

It introduces a new HARQ scheme for uplink RSMA with variable retransmission times and a power allocation strategy, enhancing reliability and efficiency.

Findings

RSMA outperforms NOMA and FDMA in error probability

RSMA with HARQ reduces power consumption

The proposed scheme improves transmission reliability

Abstract

Rate-splitting multiple access (RSMA) has attracted a lot of attention as a general and powerful multiple access scheme. In the uplink, instead of encoding the whole message into one stream, a user can split its message into two parts and encode them into two streams before transmitting a superposition of these two streams. The base station (BS) uses successive interference cancellation (SIC) to decode the streams and reconstruct the original messages. Focusing on the packet transmission reliability, we investigate the features of RSMA in the context of hybrid automatic repeat request (HARQ), a well-established mechanism for enhancing reliability. This work proposes a HARQ scheme for uplink RSMA with different retransmission times for a two-user scenario and introduces a power allocation strategy for the two split streams. The results show that compared with non-orthogonal multiple access (NOMA) and frequency division multiple access (FDMA), RSMA outperforms them in terms of error probability and power consumption. The results show that RSMA with HARQ has the potential to improve the reliability and efficiency of wireless communication systems.